US1808578A - Rubber composition and method of preserving rubber - Google Patents

Description

7 No Drawing.

Patented June 2, 1931 UNITEDgSTATES PATENT OFFICE",

WALDO L. SEIIION, OF OUYAHOGA FALLS, OHIO, ASSIGNOR TO THE B. I. GOODRIOH COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK RUBBER COMPOSITION AND METHOD OF PRESERVING RUBBER This invention relates to the art ofpre-i serving rubber, either in a vulcanized or unvulcanized condition, and to rubber compositions so preserved.

It is well known that rubber deteriorates more or less rapidly upon aging, especially when exposed to light, heat, or air. It has heretofore been proposed to retard such deterioration by treating therubber, either before or after vulcanization, with so-called anti-oxidants. An object of this inven tion is accordingly to provide a new class of 7 brom-diphenylamine, naphthylamine,

erties, it is preferred to employ such as contain the substituent in the para position relative to the secondary amino group, since the the meta compounds.

para substituted secondary amines are more active as anti-oxidants than the ortho compounds, which in turn are more active than Vhen incorporated into rubber compositions before vulcanization, the above-mentioned halogen substituted diarylamines are extremely effective n retarding their deterioration, compositions so treated being capable of withstanding the deleterious eifect of exposure to oxidizing materials or tothe elements without sensible deterioration for a far longer period than untreated compo-- sitions. The anti-oxidants are preferably employed in the proportions of from part to parts by weight for every 100 parts of rubber.

As a specific example of one embodiment Althou h such substituted amines ini 23 i general exhibit valuable anti-oxidant propl After 7 hrs. in the g; ag days in the Bierer- Anttoxidant 7 Geer oven vDavis V bomb 7 'l E 'r -E "'r E None (control) 3525 662' 204i 476 815 340 tribromplienylalpha o 1 naphthylamine 3634 690 2173 493 1548 480 p, p ditirom-diphenyll amine 3513 633 2817 530 2246 530 o-chlorphenyl-beta-naphthylamine 3334 673 1903 497 1695 510 p-chlorphenyl-betanaphthylamine 3677 683 3241 567 2701 603 p-chlorphenylalpha I methyl-beta-naphthyh 3773 650 2605 517 2000 557 amine r Application filed January 17, 1930. Serial No. 421,597.

ofthe method of this invention, a typical tire tread composition was prepared containing: blendedplantation rubbers 100 parts-by weight, sulfur 5.5 parts, zinc oxide parts, gas black 40 parts, mineral rubber 10 parts, palm oil 5 parts, and hexam-ethylene tetramine 0.7 5 parts. A portion of the composition was used as a control while 0.95parts (0.5% of the weight of the composition) of one of the above-describedanti-oxidants were added to other portions. The compositions were thoroughly mixed, and vulcanized in a press for minutes at 145? G. (294 F.) to producean optimum cure. The relative rates of aging of the vulcanized compositions were compared by measuring their respective tensile strengths and elongations' before and after aging. Accelerated aging tests were carried out in the Greer ageing oven, in which samples were maintained at a temperature of- C. (158 F.) in a constantly renewed stream of air, as well-as in the Bierer-Davis bomb, in which other samples were main-" tained at the sametemperature (70 C.) in

an: atmosphere of oxygen at a pressure of i 300 lbs. per sq. in. .tInthe table below .T indicates ultimate tensile strength in pounds per sq. in; and E indicates ultimate elonga-' tion in percent oforiginal length. I

Aging tests of substituted diary laminae After 48 It is evident from the above examples that rubber compositions containing even small proportions of the anti-oxidants of this invention resist deter oration far more effectively than the similar untreated composi-..

tions. 7 7

Obviously, the practice of this invention is not limited to the specific compositions given above, such compositions being merely illustrative of one manner of employing the anti-oxidants of this invention; :The proportions of the Constituents may be varied, or

other substances may be substituted therefor, since thls invention is applicable to pure rubber or rubber compositions of the most varied nature. The anti-oxidants may be applied tounvulcanized or vulcanized rubber :With

'good eflect on the. age-resisting properties of the rubber, such as by applying them to the surface of the rubber, as for example in solution, or in the form of a paste or emulsion.

It is to be understood that the term treating as employed: in the appended claims is used in a. generic sense to include either the 1ncorp0rat1on of the anti-oxidants into the rubber by mllling'orsnnllar process, or their addition to the rubber latex before the ooagulation, or to the application thereof to the surface of a mass of crude or. vulcanized rubber The term rub ber islikewise employed in the claims in a generic'sense to include caoutchouc, whether natural or synthetic, reclaimed rubber, balata, gutta percha,

7 rubber isomers and like products, Whether or not admixed with fillers, pigments, vulcanizing or accelerating-agents.

W'hile I have herein disclosed certain pre ferred manners of performing my invention, I do not thereby desire or intend to limit myself solely thereto, for, as hitherto stated, the precise proportions of the materials utilized may be varied and other materials having equivalent chemical properties may be employed if desired without departing from the spirit andrscope oftheinvention as de- 7 lined in the appended claims. "I claim; I

1. The method comprises treating rubber with a g V halogen substituted diarylamine.

en'rhe method of preserving rubber which comprisestreating' rubber with a halogen "substituted diarylamine, at least one of the fsubstituents being located in the para positron relative to the amino group.

g 3. The methodof preserving rubber which" .comprlses. treating rubber with a halogen substituted aryl-naphthylamine.

4. The methodof preserving rubber which 'celerator of vulcanization, and a halogen subof preserving rubber which r 6. The method of preserving rubber which comprises treating rubber with a p-chlor- I phenyl naphthylamine.

7. The method of preserving rubberwhich comprises treating rubber with pchl'orphenyl-beta-naphthylamine. I

8. A composition of matter comprising 'rubber and a halogensubstituted aryl-'naph thylamine.

11. A composition of matter comprising rubber and a halogen substituted phenyl- 7 naphthylamine. 7

12. A composition of matter comprising rubber and a mono-halogen substituted phenyl-naphthylamine, the halogen being located in the para position relative to the secondary amino group. v

13. A composition of matter comprising rubber and a pchlorphenylsnaphthylamine.

14. A compositioniof matter comprising rubber and p-chlorphenyl-beta-naphthylamine.

' 15. A vulcanized rubber product resulting from the vulcanization of a. composition comprising rubber, a vulcanizing agent, an accelerator of vulcanization, and a halogen substituted diarylamine. o

16. A vulcanzed rubber product resulting from thevulcanizationofa composition comprising rubber, a vulcanizing agent, an ac-.

stituted .phenyl-naphthylamine.

17. Avulcanizedirubber product resulting from the vulcanization of a composition comprising rubber, a Vulcanizing agent, an accelerator-of vulcanization, I and p-chlorphenyl-beta-naphthylamine.

In witnesswhereof I have hereunto setinj hand this 9th day of January, 1930.

. .WALDO,-L., SEMON.

comprises. treating rubber with a halogen substituted phenyl naphthylamine.

5. The method of preserving rubber which comprises treating rubber with a mono-hal0 gensubstituted phenyl naphthylamine, the

V halogen being located on the phenyl groupin the para-position relativetothe an'iino group.